Method and system for simultaneous irradiation and elution capsule

ABSTRACT

A capsule for holding, irradiating, and eluting a material is provided. Methods of fabricating and using the capsule are also provided. The capsule may include a multidiameter tube with a first end region, a second end region, and a middle region. Washers and filters are provided in the end regions and the end regions may be sealed using various methods and materials with the end caps press fit into the end regions. The middle region is designed to store a material to be irradiated by a neutron flux source. The capsule components may be made from materials having a low nuclear cross section so that the capsule may be handled safely after an irradiation step is performed. The capsule is also designed to have a symmetric configuration as an elution and irradiation column so that the same capsule may be used to elute the material within the middle region of the capsule after an irradiation step is performed.

CROSS REFERENCE TO APPLICATIONS

This application is a divisional of U.S. application Ser. No. 12/385,665filed on Apr. 15, 2009, the contents of which is incorporated byreference in its entirety.

BACKGROUND

1. Field

The invention relates to a capsule and methods of fabricating and usingthe capsule. The capsule is designed to fit within a nuclear reactor'sneutron flux so that a material within the capsule may be irradiated inthe reactor's core. The capsule is further designed to be used straightfrom the neutron flux source and used as an elution column to removeions from within the capsule that were generated by the irradiationdecay process.

2. Description of the Related Art

Technetium-99m (m is metastable) is a radionuclide used in nuclearmedical diagnostic imaging. Technetium-99m is injected into a patientwhich, when used with certain equipment, is used to image the patient'sinternal organs. However, technetium-99m has a halflife of only six (6)hours, therefore, readily available sources of technetium-99m aredesired.

A method for obtaining technetium-99m uses a minimum of a two-stepprocess. First, titanium molybdate is placed in a capsule, which is thenirradiated in a nuclear reactor. Molybdenum-98 within the titaniummolybdate absorbs a neutron during the irradiation process and becomesmolybdenum-99 (Mo-99). Mo-99 is unstable and decays with a 66-hourhalf-life to technetium-99m (m is metastable). After the irradiationstep, the irradiated titanium molybdate is removed from the capsule andplaced in a column for elution. Subsequently, saline is passed throughthe irradiated titanium molybdate to remove the technetium-99m ions fromthe irradiated titanium molybdate.

SUMMARY

At least one example embodiment relates to an elution capsule. Inaccordance with the example embodiment, an elution capsule may include atube with a first end portion having a first inside diameter, a secondend portion having a second inside diameter, and a middle portionbetween the first end portion and the second end portion having aninside diameter smaller than the inside diameters of the first andsecond end portions. The interface between the first end portion and themiddle portion forms a first shoulder and the interface between thesecond end portion and the middle portion forms a second shoulder. Theelution capsule may also include a first washer inside the first endportion contacting the first shoulder, a first filter inside the firstend portion contacting the first washer, and a second filter inside thefirst end portion such that the first filter is between the first washerand the second filter. The first end may be sealed by a first end cap.The elution capsule may also include a second washer inside the secondend portion contacting the second shoulder, a third filter inside thesecond end portion contacting the second washer, and a fourth filterinside the second end portion such that the third filter is between thesecond washer and the fourth filter. The second end portion may besealed by a second end cap.

In accordance with at least one example embodiment, a method ofirradiating a material within an elution capsule is disclosed. Inaccordance with the example embodiment, the elution capsule may includea tube with a first end portion having a first inside diameter, a secondend portion having a second inside diameter, and a middle portion havingan inside diameter smaller than the inside diameters of the first andsecond end portions. The middle portion is between the first end portionand the second end portion and is configured to hold the material. Theinterface between the first end portion and the middle portion forms afirst shoulder and the interface between the second end portion and themiddle portion forms a second shoulder. A first washer may be inside thefirst end portion and may contact the first shoulder. A first filter maybe inside the first end portion and may contact the first washer. Asecond filter may be inside the first end portion and may be positionedsuch that the first filter is between the first washer and the secondfilter. A first end cap may be provided in the first end portion toseal-off the first end portion. A second washer may be inside the secondend portion and may contact the second shoulder. A third filter may beinside the second end portion and may contact the second washer. Afourth filter inside the second end portion may be provided such thatthe third filter is between the second washer and the fourth filter. Asecond end cap may be provided in the second portion to seal-off thesecond end portion. The method, according to the example embodiment, mayinclude placing the sealed elution capsule, with the material in themiddle portion of the elution capsule in a neutron flux source andirradiating the capsule and its contents in the reactor's core.

At least one example embodiment related to a method of eluting amaterial enclosed in a sealed elution capsule is provided. The methodincludes placing the sealed elution capsule enclosing the material intoa nuclear reactor, irradiating the sealed elution capsule and materialin a reactor, removing the sealed elution capsule and irradiatedmaterial from the reactor, and performing an elution step by puncturinga first end portion of the elution capsule with a needle to supply asolution to the elution capsule and puncturing a second end portion witha needle to provide a vacuum to draw the solution through the irradiatedmaterial to collect the eluant.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the present invention will be more clearlyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings.

FIG. 1 is a section view of an irradiation/elution capsule in accordancewith an example embodiment of the present invention;

FIG. 2 is an exploded view of an irradiation/elution capsule inaccordance with an example embodiment of the present invention;

FIG. 3 is a section view of a multidiameter tube used in anirradiation/elution capsule in accordance with an example embodiment ofthe invention;

FIGS. 4 and 5 are plan views of washers used in an exampleirradiation/elution capsule in accordance with an example embodiment ofthe invention;

FIGS. 6 and 7 are plan views of filters used in an example irradiationelution capsule in accordance with an example embodiment of theinvention;

FIGS. 8-13 are views of end caps used in an irradiation/elution capsulein accordance with an example embodiment of the invention;

FIGS. 14A/B are views of a seals for sealing the ends of an exampleirradiation/elution capsule in accordance with an example embodiment ofthe invention

FIGS. 15-16 illustrate steps for using an irradiation/elution capsule inaccordance with an example embodiment of the invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Example embodiments of the invention will now be described more fullywith reference to the accompanying drawings, in which exampleembodiments are shown. The invention may, however, be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the sizes of components may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to”, or “coupled to” another element or layer, itcan be directly on, connected to, or coupled to the other element orlayer or intervening elements or layers that may be present. Incontrast, when an element is referred to as being “directly on”,“directly connected to”, or “directly coupled to” another element orlayer, there are no intervening elements or layers present. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer, and/orsection from another element, component, region, layer, and/or section.Thus, a first element, component, region, layer, or section discussedbelow could be termed a second element, component, region, layer, orsection without departing from the teachings of example embodiments.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

Embodiments described herein will refer to plan views and/orcross-sectional views by way of ideal schematic views. Accordingly, theviews may be modified depending on manufacturing technologies and/ortolerances. Therefore, example embodiments are not limited to thoseshown in the views, but include modifications in configuration formed onthe basis of manufacturing processes. Therefore, regions exemplified infigures have schematic properties and shapes of regions shown in figuresexemplify specific shapes or regions of elements, and do not limitexample embodiments.

FIGS. 1-3 represent an example embodiment of the present invention. Theexample embodiment, as shown in FIGS. 1-3, includes a hollowcylindrically shaped multidiameter tube 10. The tube 10 is hollow suchthat a cross-section of the multidiameter tube has an annular shape. Thetube 10 has a constant outer diameter D1, however, the inner diameter ofthe tube 10 varies along the length of the tube 10. For example, thetube, as shown in FIG. 1, includes three portions: a first end portion12 located at one end of the multidiameter tube 10, a second end portion14 located at another end of the multidiameter tube 10, and a middleportion 16 between the first end portion 12 and the second end portion14. In this example embodiment of the invention, the inner diameter D4of the middle portion 16 may be smaller than the inner diameters D2 andD3 of the end portions 12 and 14. In addition, the inner diameter of thefirst end portion D2 and the inner diameter of the second end portion D3may be equal.

The first end portion 12 and the second end portion 14 may have lengthsP1 and P2, respectively. As shown in FIG. 3, the lengths P1 and P2 maybe equal. The interface between the first end portion 12 and the middleportion 16 forms a first shoulder 100 and the interface between thesecond end portion 14 and the middle portion 16 forms a second shoulder110. Because the lengths P1 and P2 may be equal and because thediameters D2 and D3 may likewise be equal, the multidiameter tube 10illustrated in FIGS. 1-3 may have a symmetric configuration.

The example capsule 1 for holding, irradiating and eluting a material inaccordance with FIGS. 1-3 also includes first and second washers 20 and60 positioned inside the first end portion 12 and the second end portion14, respectively. The washers 20 and 60, as shown in FIGS. 1, 2, 4 and5, are short hollow cylinders with annular cross-sections. The washer 20has an outside diameter D6 larger than the inside diameter D4 of themiddle portion 16 and smaller than the inside diameter D2 of the firstend portion 12. The washer 20 has an inside diameter D5 that may besmaller, equal to, or larger than the diameter of the inside diameter D4of the middle portion 16. The washer 60 has an outside diameter D8larger than the inside diameter D4 of the middle portion 16 and smallerthan the inside diameter D3 of the second end portion 14. The washer 60has an inside diameter D7 that may be smaller, equal to, or larger thanthe diameter of the inside diameter D4 of the middle portion 16. Asshown in FIGS. 1-2, the washer 20 is placed inside the first end portion12 and against the shoulder 100. The washer 60 is placed in the secondend portion 14 and against the shoulder 110.

The example capsule 1 for holding, irradiating, and eluting a materialmay also include first and second filters 30 and 40 in the first endportion 12 and third and fourth filters 70 and 80 in the second endportion 14 of the multidiameter tube 10. The first filter 30 may beplaced in the first end portion such that the washer 20 is between thefirst filter 30 and the shoulder 100 and the second filter 40 may beplaced in the first end portion 12 such that the first filter 30 isbetween the second filter 40 and the washer 20. The third filter 70 maybe placed in the second end portion 14 such that the washer 60 isbetween the third filter 70 and the shoulder 110 and the fourth filter80 may be placed in the second end portion 14 such that the third filter70 is between the fourth filter 80 and the washer 60.

The first through fourth filters may be made of various materials. Forexample, the first filter 30 and the third filter 70 may be made fromglass wool. The glass wool may be made from a borosilicate or quartzglass. The second filter 40 and the fourth filter 80, may be circularglass frits as shown in FIGS. 1, 2, and 6-7 which resemble shortcylinders or disks. The glass fits may be made from various materialssuch as borosilicate glass, quartz glass, polyethylene, resin, or someother material that will structurally support a material within theelution tube and act as a filter to prevent material from traversingdown a flow path through the elution tube. The circular glass frit 40has an outer diameter D9 smaller than the inner diameter D2 of the firstend portion 12 but greater than the inner diameter D5 of the washer 20.The circular glass frit 80 has an outer diameter D10 smaller than theinner diameter D3 of the second end portion 14 but larger than the innerdiameter D7 of the washer 60. Although circular glass frits are used assecond and fourth filters 40 and 80, the invention is not limitedthereto.

The example capsule 1 for holding, irradiating, and eluting a materialmay also include end caps 50 and 90 configured to seal the first endportion 12 and the second end portion 14 of the multidiameter tube 10,respectively. In accordance with the example embodiment illustrated inFIGS. 1-2, the end caps 50 and 90 may include tapered hollow cylindricalbody parts 52 and 92 with covers 53 and 93 as shown in FIGS. 1, 2 and8-13, allowing the end caps 50 and 90 to be press fit into the first andsecond end portions 12 and 14 of the multidiameter tube 10. Because theends of the multidiameter tube 10 are sealed by press fitting the endcaps 50 and 90 into the first and second end portions 12 and 14, the endcaps 50 and 90 should be made from a soft material which willaccommodate yielding during the press fit process. For example, the endcaps may be made of aluminum.

The hollow cylindrical body part 52 may be tapered so that the outerdiameter D12 of a portion of the hollow cylindrical body part 52 facingthe center of the multidiameter tube 10 is smaller than an outerdiameter D14 of the hollow cylindrical body part 52 attached to thecover 53. The diameter D12 must be smaller than the inner diameter D2 ofthe first end portion 12 of the multidiameter tube 10 so that the end ofthe hollow body part 52 facing the center of the multidiameter tube 10may enter the first end portion 12. However, the outer diameter D14 ofthe cylindrical body part 52 attached to the cover 53 should be slightlylarger than the inner diameter D2 of the first end portion 12 of themultidiameter tube 10 so that when the end cap 50 is press fit into thefirst end portion 12 of the multidiameter tube 10 the first end portionis sealed. Additionally, the inner diameter D11 of the hollow body part52 should be smaller than the diameter D9 of the frit 40 to prevent thefrit 40 from passing into the hollow body part 52.

The length L1 of the hollow body part 52 should be long enough toaccommodate a needle which may be passed through the cover 53 during anelution process. The length L1 of the hollow body part 52, therefore,should be at least as long as the needle used to introduce or remove aliquid into or from the example capsule 1 for holding, irradiating, andeluting a material. Because the length L1 of the hollow body part 52 isat least as long as the aforementioned needle, the hollow body partprotects the first and second filter from being damaged by the needle asthe needle is introduced into the capsule.

The cover 53 of the end cap 50 has a diameter D15 larger than the innerdiameter D2 of the first end portion 12 of the multidiameter tube toprevent the end cap 50 from completely passing into the first endportion 12. Because the cover 53 acts as a stop, the first and secondfilters 30 and 40 may be protected from being crushed by the hollow body52 of the end cap 50 during the press fit process. Additionally, thecover 53 of the end cap 50 should be thin enough to allow puncture by aneedle used in an elution process.

The hollow cylindrical body part 92 may be tapered so that the outerdiameter D16 of a portion of the hollow cylindrical body part 92 facingthe center of the multidiameter tube 10 is smaller than an outerdiameter D18 of the hollow cylindrical body part 92 attached to thecover 93. The diameter D16 must be smaller than the inner diameter D3 ofthe second end portion 14 of the multidiameter tube 10 so that the endof the hollow body part 92 facing the center of the multidiameter tube10 may enter the second end portion 14. However, the outer diameter D18of the cylindrical body part 92 attached to the cover 93 should beslightly larger than the inner diameter D3 of the second end portion 14of the multidiameter tube 10 so that when the end cap 90 is press fitinto the second end portion 14 of the multidiameter tube 10 the secondend portion 14 forms a mechanical seal. Additionally, the inner diameterD17 of the hollow body part 92 should be smaller than the diameter D10of the frit 80 to prevent the frit 80 from passing into the hollow bodypart 92.

The length L2 of the hollow body part 92 should be long enough toaccommodate a needle which may be passed through the cover 93 during anelution process. The length L2 of the hollow body part 92, therefore,should be at least as long as the needle used to introduce or remove aliquid into or from the example capsule for holding, irradiating, andeluting a material. Because the length L2 of the hollow body part 92 isat least as long as the aforementioned needle, the hollow body part 92protects the third and fourth filters 70 and 80 from being damaged bythe needle as the needle is introduced into the capsule.

The cover 93 of the end cap 90 has a diameter D19 larger than the innerdiameter D3 of the second end portion 14 of the multidiameter tube 10 toprevent the end cap 90 from completely passing into the second endportion 14. Because the cover 93 acts as a stop, the third and fourthfilters 70 and 80 may be protected from being crushed by the hollow body92 of the end cap 90 during the press fit process. Additionally, thecover 93 of the end cap 90 should be thin enough to allow puncture by aneedle used in an elution process.

An adhesive may be applied to the outer surfaces of the hollow bodyparts 52 and 92 before the end caps 50 and 90 are press fit into thefirst and second end portions 12 and 14. The adhesive may provideadditionally sealing to prevent materials in the capsule from escaping.

The example capsule 1 for holding, irradiating, and eluting a materialmay also include a first and second seals 200 and 300 for covering theend caps 50 and 90 after the end caps 50 and 90 have been press fit intothe first and second end portions 12 and 14, respectively. Examples ofthe seals 200 and 300 are illustrated in FIG. 14. The first and secondseals include a hollow cylindrical body parts 210 and 310 and are closedat one end by end parts 220 and 320. The seals may be made from aflexible material, for example, a non-hardening rubber, so that theseals 200 and 300 can be snug fit over the first and second end portions12 and 14 to create a second seal. The end parts 220 and 320 of theseals 200 and 300 must be thin enough to allow puncture by a needle usedin an elution process. Additionally, the seals 200 and 300 may beepoxied onto the ends of the multidiameter tube 10 by applying epoxy tothe inner surfaces of the cylindrical body parts 210 and 310 before theseals 200 and 300 are fitted over the first and second end portions of12 and 14. The epoxy applied to the inner surfaces of the cylindricalbody parts 210 and 310 may provide an extra seal to prevent materialswithin the capsule 1 from escaping.

The multidiameter tube 10, the end caps 50 and 90, and the washers 20and 60, should be made from materials that have a low nuclear crosssection to avoid absorbing neutrons. Examples of such materials includezirconium, quartz, aluminum or alloys including zirconium, quartz, glassand aluminum. For example, the multidiameter tube 10, end caps 50 and90, and the washers 20 and 60, may be made from zircaloy-2 oralternatively from aluminum 6061, high purity aluminum, and 4N and 5Naluminum.

Materials having low nuclear cross section are readily available frommanufacturers and are often provided as bar stock. For example,cylinders of zirconium are readily available.

The multidiameter tube 10 may be fabricated by implementing a series ofboring operations on a solid cylinder, for example, a solid cylinder ofzirconium. The cylinder may have an outer diameter D1 and a length. Thelength of the cylinder may be determined based on the size of thenuclear reactor in which the cylinder will be irradiated and/or the sizeof a generator used in an elution process. A center of the cylinder maybe bored out to a diameter of D4 transforming the solid cylinder into ahollow cylindrical tube. The hollow cylindrical tube may have a constantannular cross section with an inner diameter D4 and an outer diameterD1.

One end of the hollow tube may have the diameter increased by a secondboring operation to form a first end portion 12 having a length of P1and an inner diameter of D2. A second end of the hollow tube maylikewise have the diameter increased by a third boring operation to forma second end portion 14 having a length P2 and an inner diameter D3. Thelength P1 should be deep enough to accommodate the above describedfilters 30 and 40, the washer 20, and the hollow part 52 of the end cap50. Likewise, the length P2 should be deep enough to accommodate theabove described filters 70 and 80, the washer 60, and the hollow part 92of the end cap 90. The second and third boring operations transform thehollow cylindrical tube into a hollow multidiameter cylindrical tube 10(see FIG. 3). The first end portion 12 has an annular cross section withan inner diameter D2 and an outer diameter D1 and the second end portion14 has an annular cross section with an inner diameter D3 and an outerdiameter D1. The portion of the tube between the first end portion 12and the second end portion 14 constitutes a middle portion 16 with anannular cross section having an inner diameter D4 and an outer diameterD1.

The depths P1 and P2 of the first end portion and the second end portion12 and 14 of the multidiameter tube 10 by the second and third boringoperations may be the same. In addition, the inner diameters D2 and D3of the first and second end portions 12 and 14 may be the same.Accordingly, the multidiameter tube 10 may be fabricated to produce asymmetrical structure.

The washers 20 and 60 may be fabricated by processes similar to thoseused in making the multidiameter tube 10. Because the washers 20 and 60may be made by the same process, the process for making washer 60 isomitted for the sake of brevity.

As a starting point, washers may be fabricated from a cylinder ofzirconium having an outer diameter of D6 may be provided. The diameterD6 should be smaller than the diameter D2 associated with the first endportion 12 of the multidiameter tube 10. The cylinder may have a lengththat should be at least as long as a desired thickness for the washer.The cylinder may have the middle bored out to create a hollow tube. Thetube has an annular cross section with an inner diameter D5 and an outerdiameter D6 (see FIG. 4). An end portion of the tube may be cut along acut line to form the washer 20 with a desired thickness.

The end caps 50 and 90 may be fabricated by processes similar to thoseused in making the multidiameter tube 10. Because the end caps 50 and 90may be made by the same process, the process for making the end cap 90is omitted for the sake of brevity.

As a starting point, end caps may be fabricated by a cylinder ofzirconium having an outer diameter D14 may be provided. The diameter D14should be larger than the diameter D2 of the first end portion 12 of themultidiameter tube 10 (see FIG. 3). The cylinder is slightly longer thana length of a needle used to introduce or remove saline solution into orfrom the capsule 1 during the elution process. The cylinder may beplaced in a die which fixes a portion of the cylinder. A first force maybe applied to one end of the cylinder to deform the end of the cylinderto create a cover 53. The cover has a diameter D15 larger than thediameter D14 of the cylindrical body 52.

After the cover 53 has been formed, a portion of the cylinder below thecover 53 may be bored out to create a hollow body portion. The hollowbody portion resembles a circular tube having an annular cross sectionwith an inner diameter D11 and an outer diameter D14. After the hollowbody portion is formed, a second force may be applied laterally to thehollow body portion to deform the hollow body portion into a taperedshape. Application of the second force transforms the hollow bodyportion into a tapered hollow body 52. The end of the tapered hollowbody 52 away from the cover 53 has an annular cross section having aninner diameter D11 and an outer diameter D12. The outer diameter D12should be formed to be smaller than the inner diameter D2 of the firstend portion 12 in order to allow the end cap 50 to enter into the firstend portion 12.

Having fabricated the multidiameter tube 10, the washers 20 and 60, andthe end caps 50 and 90 the capsule 1 may be assembled as shown in FIG.2. The washer 20 may be placed into the first end portion 12 so that thewasher 20 bears up against the first shoulder 100. A first filter 30,for example, glass wool made from borosilicate glass, may be placed inthe first end portion 12 so that washer 20 is between the first filter30 and the shoulder 100. A second filter 40, for example, a glass fritmade of borosilicate glass, may be provided in the first end portion 12so that first filter 30 is between the second filter 40 and the washer20. The end cap 50 may be inserted and press fit into the first endportion 12 thus sealing the first end portion 12. An epoxy may beprovided on the outer surfaces of the hollow body part 52 of the end cap50 before the press fitting operation to provide an extra added sealingmeans.

Formation of the capsule is completed by sealing the second end. Thewasher 60 may be placed into the second end portion 14 so that thewasher 60 bears up against the second shoulder 110. A third filter 70,for example, glass wool made from borosilicate glass, may be placed inthe second end portion 14 so that washer 60 is between the third filter70 and the shoulder 110. A fourth filter 80, for example, a glass fritmade of borosilicate glass, may be provided in the second end portion 14so that third filter 70 is between the fourth filter 80 and the washer60. The end cap 90 may be inserted and press fit into the second endportion 14 thus sealing the second end portion 14. An epoxy may beprovided on the outer surfaces of the hollow body part 92 of end cap 90before the press fitting operation to provide an extra added sealingmeans.

In addition to the above steps for fabricating the example capsule 1,extra seals 200 and 300 (see FIGS. 2 and 14) may be provided and placedon the ends of the capsule 1 after the first and second end portions 12and 14 are sealed. The seals 200 and 300 may be provided for an extraseal. These seals may be made from a flexible material such as rubberand may be fabricated to provide a snug fit over the end portions of 12and 14, of the capsule 1. The seals may include hollow body parts 210and 310 and cover parts 220 and 320. The cover parts 220 and 320 shouldbe sufficiently thin to allow for puncture by a needle in an elutionprocess. In addition, epoxy may be applied to the inside surfaces of thehollow body parts 210 and 310 before the seals 200 and 300 are placed onthe end portions 12 and 14 to provide for extra means for sealing theend portions of 12 and 14, of capsule 1.

As disclosed, the example capsule 1 includes a multidiameter tube 10with a first end portion 12, a second end portion 14, and a middleportion 16 between the end portion 12 and 14. When the tube is in use,the middle portion 16 holds a material for an irradiation process. Forexample, the middle portion 16 may hold titanium molybdate, zirconiummolybdate, titanium tungstenate, zirconyl tungstenate, or other ionexchange resin/gel matrix for elution. The material, for example, may beadded to the middle portion 16 after the first end portion 12 has beenassembled and sealed by the end cap 50 as described above. After thematerial is added to the middle portion 16, the second end portion 14may be assembled and sealed as described above.

The sealed capsule 1 (without the seals 200 and 300) including thematerial to be irradiated may be irradiated in a nuclear reactor. Afterthe irradiation step, the capsule may be removed from the reactor andthe seals 200 and 300 may be fixed to the capsule as described above.Referring to FIGS. 15 and 16 a method of eluting the ions generated bythe irradiation step and subsequent radioactive decay is described.

As shown in FIGS. 15 and 16, the capsule 1 includes an irradiatedsubstance 6000. The elution process comprises two steps. The first stepincludes puncturing one end of the capsule 1 with a needle 7100 attachedto a device 7000 for supplying a liquid, for example, distilled water,deionized water, saline, oxidizers, acids, bases, or any other waterbased solution, to the example capsule 1. As shown in FIG. 15, the seal200 and the end cap 50 may be punctured by the needle 7100. However,because the length of the needle is shorter than the length of thehollow body portion 52, the first and second filters 30 and 40 ofcapsule 1, are not damaged by the needle. In order to draw the liquidthrough the irradiated substance 6000 as shown in FIG. 16, a needle 8100attached to a vacuum system 8000, e.g. a vacuum bottle, punctures theend cap 90 and the seal 300. However, because the needle 8100 is shorterthan the length of the hollow body 92 of the end cap 90, the third andfourth filters 70 and 80 of capsule 1, are not damaged by the needle8100. The vacuum from the vacuum system 8000 draws the fluid from thedevice 7000, through the irradiated material 6000, and into the vacuumsystem 8000. Accordingly, ions generated during the irradiation decayprocess may be collected in the vacuum system 8000.

While example embodiments have been particularly shown and describedwith reference to example embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the following claims.

What is claimed is:
 1. An elution capsule, comprising: a tube with afirst end portion having a first inside diameter, a second end portionhaving a second inside diameter; a singular first opening in the firstend portion and a singular second opening in the second end portion, thefirst and second openings facing opposite directions and being aboutcollinear with a longitudinal centerline of the tube; a middle portionbetween the first end portion and the second end portion and having aninside diameter smaller than the inside diameters of the first andsecond end portions, wherein an interface between the first end portionand the middle portion forms a first shoulder and an interface betweenthe second end portion and the middle portion forms a second shoulder; afirst washer inside the first end portion contacting the first shoulder;a first filter inside the first end portion contacting the first washer;a second filter inside the first end portion contacting the firstfilter, the first filter being located between the first washer and thesecond filter; a first end cap sealing the first opening; a secondwasher inside the second end portion contacting the second shoulder; athird filter inside the second end portion contacting the second washer;a fourth filter inside the second end portion contacting the thirdfilter, the third filter being located between the second washer and thefourth filter; and a second end cap sealing the second opening.
 2. Theelution capsule of claim 1, wherein the cross-sections of the first endportion, the second end portion, and the middle portion are annular. 3.The elution capsule of claim 1, wherein the first inside diameter andthe second inside diameter are the same.
 4. The elution capsule of claim1, wherein a length of the first end portion and a length of the secondend portion are the same.
 5. The elution capsule of claim 1, whereinfirst and third filters are glass wool and the second and fourth filtersare one of glass frits and porous discs, the second and fourth filtersbeing formed from one of borosilicate glass, quartz glass, polyethylene,and resin.
 6. The elution capsule of claim 5, wherein the glass woolincludes at least one of borosilicate glass wool, quartz glass wool, andglass fiber.
 7. The elution capsule of claim 1, wherein the first endcap comprises: a hollow body, wherein an outside surface of the hollowbody is tapered to allow for press fitting the first end cap into thefirst opening to create a seal at the first opening; and a coverconfigured for puncturing by needles and configured to bear against anoutside surface of the first end portion.
 8. The elution capsule ofclaim 7, wherein the hollow body of the first end cap has an annularcross section and an outside diameter of the cross section varies alongan axis of the hollow body and the cover has a solid circular crosssection with an outer diameter greater than the inner diameter of thefirst end portion.
 9. The elution capsule of claim 1, wherein the firstwasher has an annular cross section with an outside diameter less thanthe first inside diameter of the first end portion and the second washerhas an annular cross section with an outside diameter less than thesecond inside diameter of the second end portion.
 10. The elutioncapsule of claim 1, wherein the tube is made from at least one of highpurity zirconium, aluminum, glass and quartz.
 11. The elution capsule ofclaim 1, further comprising: a first epoxy layer between the first endcap and the first end portion and a second epoxy layer between thesecond end cap and the second end portion.
 12. The elution capsule ofclaim 1, further comprising: a first flexible seal on an outside of thefirst opening and a second flexible seal on an outside of the secondopening.
 13. The elution capsule of claim 12, further comprising: afirst adhesive layer between the first flexible seal and the first endportion and a second adhesive layer between the second flexible seal andthe second end portion.
 14. A system, comprising: the elution capsule ofclaim 1, wherein material is included in the middle portion of theelution capsule, the material including one of titanium molybdate,zirconium molybdate, titanium tungstenate, and zirconyl tungstenate. 15.The system of claim 14, further comprising: a nuclear reactor having aneutron flux, wherein the elution capsule is in the neutron flux of thenuclear reactor.
 16. The system of claim 14, wherein, the first endportion of the elution capsule is configured to be punctured by anelution needle to supply elution solution into the elution capsule inorder to contact the material, the second end portion of the elutioncapsule is configured to be punctured by a vacuum needle to provide avacuum to draw the elution solution through the material to collect aneluant.
 17. The system of claim 16, wherein the elution solution is oneof distilled water, deionized water, saline, oxidizers, acids or bases.